Separation of minerals by froth flotation



United States Patent SEPARATION OF MINERALS BY FROTH FLOTATION EdmundJames Pryor, Hendon, London, and Marston Greig Fleming and StanislawAleksander Wrobel, London, England No Drawing. Application April 26,1952, Serial Nth-284,648 Claims priority, application Great BritainMarch 11, 1952 10 Claims. (Cl. 209 166) This invention relates toimprovements in or relating to the separation of minerals by frothflotation.

For the eflicient separation of ores by froth flotation, it is usuallynecessary or desirable to condition the surfaces of the small particlesof the various minerals present in the pulp, i. e. in the aqueoussuspension of ore-particles produced by comminution. For this purposeactivating and depressing chemicals are usually added, and these areusually followed by, or used contemporaneously with collector agents,the general effect being to develop a tendency in one type of particleto become aerophilic or hydrophobic and then to unite withp'assing airorgas-bubbles which rise to the surface of the pulp and form a mineralisedfroth containing a high concentration of such particles, while at thesame time the other particles in the pulp develop oppositecharacteristics or remain indifferent, so that most of them remainwetted in the pulp under the aerating or gasifying conditions which areextractingthe aerophili'c mineral.

For high efficiency of extraction, it is desirable that only smallquantities of chemical be used, so "as to aid their specific reactionwith the particles; to maintain conditions in which these reagents arefully mobile and dispersed so that they can search the whole of thepulp; and to achieve a freely breaking froth when the mineralisedbubbles rise, so that any hydrophilic particles which have becomeentrained in the froth can easily drop back into the pulp and thus donot contaminate the mineral being removed with the froth.

Commercial oleic acid, which is used industrially in large quantities asa collector agent in. froth flotation processes, for example forseparating fluorite (Ca Fz') from fluorspar ore, solidifies at about 14C. It is generally necessary to heat the pulp far above this temperaturein order to promote good dispersion of the collector agent duringconditioning. There is the further diflieulty that when the froth risesit may cool sufficiently for the oleic acid to freeze somewhat, thusproducing a sullen froth which does not break or run freely, or afla-shfloa-t which forms and then can only'be broken down withdifficulty, thus locking up undesired mineral andreducing the purity ofthe desired product as Well as increasing the difliculty of handling thefrothed product. There is the further difficulty that when an envelopeof frozen agent forms around any particle. that particle reacts to theformed surface and not to its inherent composition, so that particleswhich are by nature hydrophilic react under such circumstances as thoughthey are hydrophobic, and thus are floated when it is desired that theyremain sunk.

For these reasons it is desirable that collector agents should remainunfrozen. at Working temperatures. In the case of oleic acid thisentails the introduction of heat into the flotation plant. This iscostly, and caninterfere with the reaction of the air or other gas withthe pulp.

It is an object of this invention to provide a new oleic acid collectoragent complex which is partlywatensoluble and is wholly dispersed in theform of a stable emulsion on addition of water.

It is a further object to provide a new oleic acid collector agentcomplex which is a mobile dispersed agent at temperatures as low as C.and confers high selectivity and excellent mobility upon the freerunning mineralised froth resulting from its use in flotation, even Whenquantities as small as 0.1% are used.

it is a still further object of this invention to provide. a process forthe production of the said new oleic acid collector agent complex. I

. Yet another object of this invention is to provide a process for theseparation of minerals by froth flotation employing the said new oleicacid collector agent complex.

Still another object of this invention is to provide a froth flotationprocess which enables calcium fluorite to be floated away from silica,shale, calcite and other minor contaminants in naturally occurringfluorspar ore in pulps produced during mill treatment using unheatedwater with the production of mineralised froths so clean that on dryingthey are found on assaying to contain more than 98% CaFz. I

The present invention provides a process for the production of acollector agent complex for use in the separation of minerals by frothflotation, which comprises making an aqueous dispersion of one part byweight of the free acids or the sodium salts of a mixture of petroleumsulphonic acids obtained by sulphonation of a high boiling petroleumfraction, the said mixture being characterised by the solubility of itssodium salts in water, mineral hydrocarbon oils, oleic acid, benzene andchloroform, by partial solubility of said sodium salts in hydrochloricacid and by formation of water-insoluble calcium and barium salts;heating said aqueous dispersion to boiling'; mixing said aqueousdispersion (when the free acids are employed and preferably also whenthe sodium salts are employed) with an aqueous solution of one-third to8 parts by weight of sodium silicate; adding water to give an aqueoussuspension containing a total quantity of water varying within the rangeof 8 to 50 parts by weight in direct proportion to the quantity of oleicacid subsequently added; bringing 2 to 50 parts by weight of liquidoleic acid gradually into reaction with said last-mentioned aqueousdispersion by agitation of the mixture at an initial temperature of atleast 50 C.; and continuing agitation until the product is homogeneouson standing.

Preferably the substances specified above are employed in the followingproportions by weight, calculated on 1 part by weight of the free acidsor sodium salts of the mixture of petroleum sulphonic acids:

Sodium silicate a.. 0.5 to 5.0 Water 15 to 50 Oleic acid 10 to 50 Theinvention further provides a process for the separation of minerals byfroth flotation wherein the collector agent produced by theabove-described process is employed.

The properties of the collector agent complex are quite different fromthose of a mere mixture of its ingredients, and the flotation resultsobtainable with the complex are far superior to those obtainable with.such a mere mixture. The conditions specified above have been found tobe critical for the formation of the complex. Whilst we have no doubtthat acomplex is formed, as evidenced by the above-mentioned differencein properties, we have not been able to establish with certainty themechanism in volved. It appears that during the c'o'mplex-formation thedouble bond of some of the oleic acid is saturated and that the complexformed assists in emulsifying the re mainder of the oleic acid to give ahighly active fluid collector agent.

The nature of the above-described sodium salts of petroleum sulnhonicacids is discussed bv Reuben Sparling in Industrial and EngineeringChemistry, vol. 40 1948), pages 890 et seq. Commercial petroleumsulphonates are available which contain these salts; they may beidentified by their solubility in water, mineral hydrocarbon oils, oleicacid, benzene and chloroform, by their partial solubility inhydrochloric acid and by their formation of water insoluble' calcium andbarium salts.

Among the proprietary organic compounds which contain varying andusually unspecified quantities of sulph-onated hydrocarbon oils, we havetested the following during the development work which led to theestablish ment of the novel principles underlying the present invention.Our tests have shown that the following commercial sulphonates possessreactive powers in connection with the froth flotation of suitable ores:

Petromor Pale A, Petromor 276 and Petromor N, sold by Manchester OilRefinery Ltd. R 824 and R825, sold by American Cyanamid Company, whichbehave substantially identically in the A number of addition-a1modifying agents may be emprocess of the invention. L M W, sold by ShellChemicals Ltd.

The properties of these commercial products are tabul-ated below:

quebracho) The quantity of each modifying agent Commercial productPetromor Pale A Petromor 276 Petromor N R 824, R 825 L M W Solubility inH1O soluble soluble soluble. Solubility in hydrocarbon do do Do.

oil or oleic acid. Solubility in benzene do .-do Do. Solubility inchloroform." do d do .do Do.

Solubility in dilute hydropartially soluble... partially solublepartlally soluble partlally soluble partially soluble.

chloric acid. Solubility in Ca and Ba insoluble insoluble insolubleinsoluble insoluble.

salts in water. Flgatability Index with high hig fair high very high.

aFz.

The same commercial products, when converted into collector agentcomplexes with oleic acid by the process of the invention, exhibit thefollowing properties:

used, or of any combination of such agents should nor- 0 mally be madespecific to the particular mineral which is to be treated, sinceinterfacial (surface) reactions de- Commercial product a ggg ii ig L M WSolubility or dispersibility in good good good good... good.

water. Stability do fairly good" fairly good.. v good v. good.Collecting power with Cam..- v. good-.. good fair do excellent.Selectivity in CaFzfiOtati0n do v. good good do. Do.

In addition to the foregoing compounds, the following proprietaryproducts were similarly tested. These contain sulphates or sulphonatesother than the sodium petroleum sulphonates which are employed accordingto the present invention.

Vitanol and Petrosol, sold by Manchester Oil Refinery Ltd R 801; sold byAmerican Cyanamid Company.

Teepol, sold by Shell Chemicals Ltd., which is stated to be a syntheticproduct based on sodium higher alkyl sulphates.

Sodium cetyl sulphate.

Limsopon 100 and Limsopon 574, sold by F. W. Berk & Co. Ltd., stated toberespectively a synthetic sulphate based on dodecyl benzene containing3540% of active ingredients.

The properties of these commercial products (which differ from theabove-quoted properties of the commercial products suitable for useaccording to the invention) were proved by our tests to be as follows:

pend upon a complex group of physical and chemical characteristics whichvary even in naturally occurring ore-deposits of the same general type.Preferably the additional modifying agents are used in quantities of 5%or less of the weight of the long-chain fatty acid.

The following examples show how the process of the invention may becarried into effect:

Example 1 in order to ensure its complete dissolution.

The total mixture (temp. 57 C.) was immediately shaken vigorously untilchemical react-ion was well set Commercial product Vitanol F. S. A. R801 g; 501 T 6 1 Llnsfipon ig a Solubility in H30 partially soluble--.soluble soluble S01ub1e soluble soluble. Solubility in hydrocarbon dopartially soluble... insoluble insoluble.. do Do.

oil or oleic acid.

Solubility in benzene soluble insoluble do -d0 insoluble" insoluble.

Solubilityin chloroform"- partially soluble... partially soluble... do-do solublesoluble.

Solubilityindilute hydroinsoluble insoluble soluble. soluble..- do Do.

chloric acid.

Solubility of Ba and Ca soluble soluble do insolubledo D0.

salts in water.

Flgathability Index with low very low zero Zero zero zero.

Attempts to convert these commercial products with oleic acid intocollector agent complexes met with a complete. lack of success, themixtures having the following properties:

in and the appearance and colour of the resultant complex-productchanged from brown to creamy-white. 1.6 gms. of cresylic acid were thenadded and shaking continued for at least one hour or until the reactionwas Sodium Commercial product Vitanol R801 Petmsol Cetyl Teepol LimsoponLimsopon Sulphate 1 Solubility or dispersinone v.poor. none-. none nonenone none.

bility in water. 2 Stability -do v.poor do v.poor. v. poor. 3 Ctlehctingpower with v.poor do... v.poor .do Do.

The collector agent complex produced by the process of the invention ispartly water-soluble and is wholly dispersed in the form of a stableemulsion on addition of water. 5

substantially complete and the product appeared as a homogeneous thickfluid.

Example 2 4 P. F. 6,4.0 gms. of R 825 were dissolved byhea'ting in 20.gms. of water until the: boilingapoiut was: reached. The: mixture was:immediately takenv ed the: heat: and added. to 5.0; gms.. 01? sodiumsilicate. which had been previously dissolved in 30 gms. of warm water.The resultant mixture was shaken for a few seconds to ensurehomogeneity; 50 gms. of water were then added without further stirring,followed by immediate addition of 40 g ms. of oleic acid which waspreviously heated above 60 C. in order to ensure its complete.dissolution.

The total mixture (temp. 55 C.) was immediately shaken vigorously untilchemical reaction was well. under way and the appearance and colour ofthe resultant complex-product changed from brown to creamy-white. Theshaking was; continued for at least one hour or until the reaction was;complete and the product appeared as a homogeneous thick liquid.

Example 3 P. F. 8.-l5-.0' gms. of R 825- were dissolved by heating in-40 gms. of water until the boiling point was reached. The: mixture wasimmediately taken off the heat and added to 5.0- gms. of sodiumsilicate. which was previously dissolved. in 3.0 gms. of warm water. Theresultant mixture was shaken for a few secondsto ensure homogeneity; 50gms. of water were added without further shaking, followed by immediateaddition of 30 gms. of oleic acid was previously heated above 60 C. inorder to ensure its. complete dissolution.

The total mixture (temp. 51 C.) was immediately shaken vigorously untilchemical reaction was well under way and the appearance and colour ofthe resultant complex-product changed from brown to creamy-white.Shaking was continued for at least one hour or until the reaction wascompleted.

Example 4 P. F. 1:0..-32..0. .ofR .825 were dissolved by heating ingms.. of. water until the. boiling point. was reached. mixture wasimmediately taken 01f the. heat and added to 5.0 gms. of sodium silicatewhich was previously dissolved in gms. of warm water. Theresultantmixlure was shaken for a tow seconds to. ensure homogeneity; 60gms. of water were then added without further stirring, followed byimmediate addition of 4Ov gmsof oleic acid which was previously heatedto above 6.0? C. in order to ensure its complete dissolution.

' The total mixture (temp. 53 C.) was immediately shaken vigorouslyuntil chemical reaction was completed (at least one. hour). and theproduct appeared as a homogeneous; liquid.

Example 5 P. F. 1?.2 made with free sulphonic acid-2.0 gms.(approximately); of free sulphonic acids liberated from R825 weredissolved by heating in 10 gms. of water until the boiling point wasreached. The mixture was immediately taken off the heat and added to 2.0gms. of sodium silicate which was previously dissolved in 1.0 gms.. of.warm water. The resultant mixture was shaken for a few seconds to ensurehomogeneity; 20 gms. of water were then added without further shaking,followed by immediate addition of 93.2 gms. of oleic acid which waspreviously heated above 60 C. in order to ensure its completedissolution.

The total mixture (temp. 57 C.) was immediately shaken vigorously untilchemical reaction was well set in and the appearance and colour of theresultant complexproduct changed from brown to creamy-white. 1-.6- gms.of cresyli'c acid were then added and. shaking continued for at leastone hour or until the reaction was substan tially complete and theproduct, appeared. as. a homogeneous thick liquid.

Example 6 P. F. 12 made without sodium silicate.. 4. (l gms. of R 825were dissolved by heating in 20 gms. of water until the boiling pointwas reached- The. mixture was immediately taken off the heat. 20 gms. ofwater were added without stirring, followed by 93.2 gms. of oleic acidvwhich waspreviously heated above 60 C. The total mixture. (temp. 63 C.)was immediately shaken vigorously until chemical reaction was: well setin and the appearance and colour of the resultant complex-productchanged from brown to. creamy-white. 1.6 gms. of cresylic acid were.then added and shaking continued; for at. least one hour' or until thereaction was substantially complete and the product appeared-as ahomogeneous. thick. liquid.

In the: foregoing examples: the degree. of completion of the: chemicalreaction. (depending upon the. initial temper;- ature at which mixingwas carried out but which was above 50 C. and theitotal time of mixingthe. reactants) was: tested bydropping a spot of. the product into thewater; if the reaction was. complete; the drop of the reagent wouldrapidly dissolve with somewhat violent swirling; the failure orsluggishness of dissolution would indicate the need for further mixingin order to. complete the desired reaction.

The. conversion of oleic: acid into a complex improves its fluiditydispersion. in such a manner as: to allow of improved commercialoperation at lower temperatures. In laboratory tests it has been provedthat a complex formed in this way from commercial oleic acid-is a mobiledispersed agent at temperatures as low as 5" C. conferring highselectivity and excellent mobility upon the freely running mineralisedfroth resulting from: its use in flotation even when quantities assmall. as 0.1% are used. It has been foundpossible to floatcalciumfluorite away from silica, shale, calcite and other minorcontaminants in naturally occurring fiuorspar etc in pulps producedduring mill treatment using unheated water with. the production. ofmineralised froths so clean that on drying they were found by assayingto contain more than 98% CaFz, whereas when oleic acid was used intheconventional manner with standard conditioning agents such asquebracho, sodium silicate and alkali cyanide, similar ore could not bebrought up to acid grade (+97.5% CaFz) without the use of. temperaturesexceeding 28 C. and repeated recleaning' of the original froth.

In the full scale commercial tests referred to above assays were made atregular short intervals during four days of continuous operation andthefollowing 'resuIts were proved byassay:

The. reasons for this change in behaviour are believed to include thefollowing:

(a) The. fluidity of the oleic acid collector agent com plex at lowtemperatures makes possible the use of smaller quantities, giving highselectivity of' reaction with, the fluorite particles and. assuring the.avoidance of lumps of aggregated reagent in the pulp.

' (b) The freely breaking. and running. froth can be manipulated so thatmechanically entrained particles fall back. intothe pulpleaving. verylittle beside pure fluorite to be removed as f'rothed mineral, becausethe Small quantity of collector agent complex is still fluid, and theheavy edge-adhesion effects and obdurate flocculation frequentlyencountered in this work are prevented by the modification of thereagent.

(c). The improved dispersion of the. collector agent" complex duringthepre-flotative conditioning stages of treatment aid. the sought mineralin acquiring a mono-- molecular film of collector, and this increases.the. tech,-

nical control of the activating and depressing treatment,andrendcrsconditioning independent of the need for raised temperatures.

The process of the. present invention offers theadvan tages, compared topreviously known processes, that less oleicv acid need be used, bettergrades of concentrate are produced, less heat. need be applied tothepulp circuits; tailingslosses are reduced, and technical control of theoperation can more readily be effected.

Minerals which have been floated in tests made with the new collectoragent complexes include the following:

Lead, in the form of cerussite (PbCO3),

Lead-vanadium, in the form of descloizite and vanadinite,

Zinc, in the form of smithsoni'te ('Z'nCOs) Tin, in the formof'cassi'terite ('SnOz),

Copper, in the form of" malachite (CuCO3.Cu('OH),2-')..

These. minerals were. chosen. as. being minerals which are commonly metin the field and which present diflicul' ties with standard flotationprocesses.

was ground and conditioned as described in Example 7 and then floatedwith the aid of the reagent P. F. 12 under the conditions set out above.The concentrate was re- The tests were made in a Hallirnond cell andpure minerals were treated at a pH approximately 7, using aconcentration of the reagent P. F. 12 equivalent to 100milligrams/litre. In each case the mineral floated and, as cleaned twiceonly, and the following results were obfar as visual observation canshow, flotation was better tained:

than with any known standard reagent used for these Test NO 15 Collectora ent P. F. 1.0 Whilst many of the metal sulphide minerals can be Temp 01Q floated successfully with the aid of xanthate reagents,

sphalerite (ZnS) cannot be floated efliciently by means of xanthatereagents. Tests which we have made with Oleic acid a 6 fi u sphaleritein the Hallirnond flotation cell show, how- "T" ever, that it can befloated excellently with the agent Example 31102 P. F. 12. Material.treated.A partially concentrated Cornish Tests made with coal in astandard Fagergren cell cassiterite with the following (incomplete)analysis:

show that coal may be floated excellently with the agent GOO-h P F 12Per cent Gypsum was also tested with success as follows: i 1,000 gms. ofgypsum ore ground to pass through a a 16 6 60-mesh screen (I. M. M.)were floated in a laboratory 20 flotation machine using 2.0 lb./ton ofP. F. 12 and gave the following result:

Quebracho and sodium silicate were used as modifiers and the materialwas floatedin a Fagergren SOO-gms. laboratory flotation machine withstage additions totalling Cwcentrate Percent 3.0 lbs/ton of P. F. 12.Gypsum Results:

The following examples illustrate how the separation of minerals byfroth flotation may be carried out by the A Distribu. process of theinvention: Product Weight, iggg tion of percent p S1102, Example 7 3oSD02 percent The ore treated was a Stanhopeburn fluorspar giving R h 0 tt 7 7 61 0 28 4 Oll BI 011C811 T8. 8 the followmg head assay SeavingerConcentrate 25.8 44.3 68.8 Per Cent Tailing 66.5 0.7 2.8 CaFz 713 Head100.0 10.0 100.0 Pbs $5 3 1 5-2 Example 10.Apatite 3 Ca3(PO4)CaF2 F x55513 Material treated-An iron-contaminated apatite sand U id tifi d 0,1from Uganda containing silica, zircon, magnetite, pyro- 40 chlore andbarytes.

1 lb The glrepavas gonditigned for ten minutes with 1.0 ton 3 4 an 2.0 ls. ton NazSiOa as modifiers and fi giz g zx g g ggg g t iag 3.5 lbs/tonof P. F. 12 as collector. The flotation time combination consisting ofpotassium ethyl xanthate 0.2 gf g and no Cleaning was Carned lbs/ton ofore; cresylic acid 0.05 lb./ton; pH 7.5-8.0

adjusted with soda-ash. Five minutes conditioning followed by threeminutes frothing removed about 99% of W ht fi Dj tribu. the galena, as arough concentrate needing reclean. Product j g gf tion pi The ore wasthen conditioned for five minutes with product Apame sodium silicate (1lb./ton) and twice deslimed.

Separate lots of ore were then conditioned for five concentmteflfl 8939182 9&7 minutes with 0.75 lb./ton quebracho and 0.25 lb./ton Tailings.-10.7 55.52 6.3 potassium dichromate, and treated with differentflotation 93-26 100-0 reagents at temperatures shown in the table belowand floated. One stage of scavenge and three of cleaning were applied toa rougher concentrate, and the following results were obtained:

Example 11.Magnetite from ferrosilicon Material treated.Ferrosiliconmedium used in the Test No 1 3 11 12 14 Collector agent Olele acid-"Oleic acid... Temp 30 21 O Cone. Assay (OaFi) Tail Assay (OaFz) Oleieacid (lbs/ton of ore).

heavy media separation of Swedish iron ore and contaminated withmagnetite.

The material was conditioned for ten minutes with 2 lbs/ton of sodiumphosphate and 2 lbs/ton of sodium silicate as modifiers and 3 /2 lbs/tonof P. F. 12 as collector. The rougher concentrate was cleaned once with/2 lb./ton of P. F. 12 and 1 lb./ton of NazSiOs.

At temperatures below 20 C., it was not economically possible to produce97.5% concentrate using plain oleic acid as collector.

Tests Nos. 11, 12 and 14, which were carried out by the process of theinvention show how the separation may be carried out at lowertemperatures than when oleic acid alone forms the reagent as in TestsNos. 1 and 3.

Results: Example 8 A French ore containing: Assays Percent 5323.3

Per cent roduct ggiigg CaFz 57.4 F F O F c co 3.0 e- 1 e: 4 e 1 es 4SiO:; 36.4 Fe2O3 23 Cleanerconcentrate 13.8 16.8 82.3 2.8 03.0 Cleanertailings 0.7 45.2 34.8 0.4 2.0 Umdentfied Rougher tailings s5. 5 92. 07. 4 96.8 35. 0 Head 100.0 81.6 18.3 100.0 100.0

What we claim is:

'1. A process tor the production of a collector agent complex for use inthe separation of minerals by froth flotation, which comprises making"an aqueous dispersion of one part by weight of a member of the groupconsisting of the free acids and the sodium salts of a mixture ofpetroleum sulphonic acids obtained by sulphonation of a high-boilingpetroleum fraction, the said mixture being characterised by thesolubility of its sodium salts in water; mineral "hydrocarbon oils,oleic acid, benzene and chloroform, by partial solubility of said sodiumsalts in bydroch'loric acid "and by formationiof water-insoluble calciumand barium salts; heating said aqueous dispersion to boiling; mixingsaid aqueous dispersion with an aqueous solution of one-third to 8 partsby weight of sodium silicate; adding water to given an aqueoussuspension containing a total quantity of water varying'w-ithin therange of 8 to 50 parts by Weight in direct proportion to the quantity ofoleic acid subsequently added; bringing 2 to 50 parts by weight ofliquid oleic acid gradually into reaction with said last-mentionedaqueous dispersion by agitation of the mixture at an initial temperatureof at least 50 C.; and continuing agitation until the product ishomogeneous on standing.

2. A process for the production "of a collector agent complex for use inthe separation of minerals biy froth flotation, which comprises makingan aqueous dispersion of one part by Weight of a member of the groupconsisting'o'f the free acids and the sodium salts of a m-ixture ofpetroleum sulphonic acids obtained by sulphonation of a high-boilingpetroleum fraction, the said mixture being characterised by thesolubility of its sodium salts in water, mineral hydrocarbon oils, oleicacid, benzene and chloroform, by partial solubility of said sodium saltsin hydrochloric acid and by formation of water-insoluble calcium andbarium salts; heating said aqueous dispersion to boiling; mixing saidaqueous dispersion with an aqueous solution of one-half to 5 parts byweight of sodium silicate; adding water to give an aqueous suspensioncontaining a total quantity of water varying within the range of to 50parts by weight in direct proportion to the quantity of oleic acidsubsequently added; bringing 10 to 50 parts by Weight of liquid oleicacid gradually into reaction With said last-mentioned aqueous dispersionby agitation of the mixture at an initial temperature of at least 50 C.;and continuing agitation until the product is homogeneous on standing.

3. A new, partly water-soluble, collector agent complex, whollydispersible in water to form a stable emulsion, comprising a complexformed from oleic acid by making an aqueous dispersion of one part byweight of a member of the group consisting of the free acids and thesodium salts of a mixture of petroleum sulphonic acids obtained bysulphonation of a high-boiling petroleum fraction, the said mixturebeing characterized by the solubility of its sodium salts in Water,mineral hydrocarbon oils, oleic acid, benzene and chloroform, by partialsolubility of said sodium salts in hydrochloric acid and by formation ofwater-insoluble calcium and barium salts; heating said aqueousdispersion to boiling; mixing said aqueous dispersion with an aqueoussolution of onethird to 8 parts by weight of sodium silicate; addingWater to give an aqueous suspension containing a total quantity of Watervarying Within the range of 8 to 50 parts by weight in direct proportionto the quantity of oleic acid subsequently added; bringing 2 to 50 partsby weight of liquid oleic acid gradually into reaction with saidlast-mentioned aqueous dispersion by agitation of the mixture at aninitial temperature of at least 50 C.; and continuing agitation untilthe product is homogeneous on standing.

4. A method of separating minerals one from another which comprisessubjecting a mixture of said minerals to froth flotation in the presenceof an oleic acid collector agent complex formed by making an aqueousdispersion of one part by weight of a member of the group consisting ofthe free acids and the sodium salts of a mixture of petroleum sulphonicacids obtained by sulphonation of a high-boiling petroleum fraction, thesaid mixture being characterised by the solubility of its sodium saltsin water, mineral hydrocarbon oils, oleic acid, benzene and chloroform,by partial solubility of said sodium salts in hydrochloric acid and byformation of water-insoluble calcium and barium salts; heating saidaqueous dispersion to boiling; mixing said aqueous dispersion with anaqueone solution of one-third to- 8 parts by Weight of sodium silicate;adding water to. give. an aqueous suspension -conraining a totalquantity of water varying within the range of 8 to 50 parts by weight indirect proportion to the quantity of oleic acid subsequently added;bringing -2 to '50 parts by weight-of liquid 'oleic acid gradually intoreaction with said last-mentioned aqueous dispersion by agitation "ofthe mixture at an initial temperature of at least 50 'C.; and continuingagitation until the product is homogeneous on standing.

5. A method of separating 'fiuorite from an orc containingfiuorspar,which comprises subjecting said ore to froth flotation in the presenceof an oleic acid collector agent complex formed by making an aqueousdispersion of one part by weight of a member of the group con sisting ofthe free acids and the sodium salts of a :mixture of petroleum sulphonicacids obtained by sulphonation of a =highboiling petroleum fraction, thesaid mixture being characterised by the solubility of its sodium salts:in water, mineral hydrocarbon oils, =oleic. acid, benzone andchloroform, by partial solubility of said sodium salts in hydrochloricacid and by formation of waterinsoluble calcium and barium salts;heating said aqueous dispersion to boiling;:mixing said aqueousdispersion with an aqueous solution of one-third to 8 parts by weight of:sodiumsilicate'; adding water to give an aqueous suspension containinga total quantity of water varying within the range of -8 to 50 parts byweight in direct proportion to the quantity of 'oleic acid subsequentlyadded; bringing 2 to 50 ,parts by weight 'of liquid oleic acid graduallyinto reaction with said last mentioned aqueous dispersion by agitationof the mixture at an initial temperature of at least 50 C.; andcontinuing agitation until the product is homogeneous on standing.

6. A process for the production of a collector agent complex for use inthe separation of minerals by froth flotation, which comprises making anaqueous dispersion of one part by weight of the sodium salts of amixture of petroleum sulphonic acids obtained by sulphonation of ahigh-boiling petroleum fraction, the said mixture being characterised bythe solubility of its sodium salts in water, mineral hydrocarbon oils,oleic acid, benzene and chloroform, by partial solubility of said sodiumsalts in hydrochloric acid and by formation of water-insoluble calciumand barium salts; heating said aqueous dispersion to boiling; addingwater to give an aqueous suspension containing a total quantity of watervarying Within the range of 8 to 50 parts by Weight in direct proportionto the quantity of oleic acid subsequently added; bringing 2 to 50 partsby weight of liquid oleic acid gradually into reaction with saidlast-mentioned aqueous dispersion by agitation of the mixture at aninitial temperature of at least 50 C.; and continuing agitation untilthe product is homogeneous on standing.

7. A process for the production of a collector agent complex for use inthe separation of minerals by froth flotation, which comprises making anaqueous dispersion of one part by weight of the sodium salts of amixture of petroleum sulphonic acids obtained by sulphonation of ahigh-boiling petroleum fraction, the said mixture being characterised bythe solubility of its sodium salts in water, mineral hydrocarbon oils,oleic acid, benzene and chloroform, by partial solubility of said sodiumsalts in hydrochloric acid and by formation of Water-insoluble calciumand barium salts; heating said aqueous dispersion to boiling; addingWater to give an aqueous suspension containing a total quantity of watervarying within the range of 15 to 50 parts by weight in directproportion to the quantity of oleic acid subsequently added; bringing 10to 50 parts by weight of liquid oleic acid gradually into reaction withsaid last-mentioned aqueous dispersion by agitation of the mixture at aninitial temperature of at least 50 C.; and continuing agitation untilthe product is homogeneous on standing.

8. A new, partly water-soluble, collector agent cornplex, whollydispersible in Water to form a stable emulsion, comprising a complexformed from oleic acid by making an aqueous dispersion of one part byweight of the sodium salts of a mixture of petroleum sulphonic acidsobtained by sulphonation of a high-boiling petroleum fraction, the saidmixture being characterised by the solubility of its sodium salts inwater, mineral hydrocarbon oils, oleic acid, benzene and chloroform, bypartial solubility of said sodium salts in hydrochloric acid and byformation of water-insoluble calcium and barium 11 salts; heating saidaqueous dispersion to boiling; adding water to give an aqueoussuspension containing a total quantity of water varying within the rangeof 8 to 50 parts by weight in direct proportion to the quantity of oleicacid subsequently added; bringing 2 to 50 parts by weight of liquidoleic acid gradually into reaction with said last-mentioned aqueousdispersion by agitation of the mixture at an initial temperature of atleast 50 C.; and continuing agitation until the product is homogeneouson standing.

- 9. A method of separating minerals one from another which comprisessubjecting a mixture of said minerals to froth flotation in the presenceof an oleic acid collector agent complex formed by making an aqueousdispersion of one part by weight of the sodium salts of a mixture ofpetroleum sulphonic acids obtained by sulphonation of a high-boilingpetroleum fraction, the said mixture being characterised by thesolubility of its sodium salts in water, mineral hydrocarbon oils, oleicacid, benzene and chloroform, by partial solubility of said sodium saltsin hydrochloric acid and by formation of water-insoluble calcium andbarium salts; heating said aqueous dispersion to boiling; adding waterto give an aqueous suspension containing a total quantity of watercarrying within the range of 8 to 50 parts by weight in directproportion to the quantity of oleic acid subsequently added; bringing 2to 50 parts by weight of liquid oleic acid gradually into reaction withsaid last-mentioned aqueous dispersion by agitation of the mixture at aninitial temperature of atleast 50 C.; and continuing agitation until theproduct is homogeneous on standing.

. .10. A method of separating fluorite from an ore containing fluorspar,which comprises subjecting said ore to froth flotation in the presenceof an oleic acid collector agent complex formed by making an aqueousdispersion of one part by weight of the sodium salts of a mixture ofpetroleum sulphonic acids obtained by sulphonation of a high-boilingpetroleum fraction, the said mixture being characterisedby thesolubility of its sodium salts in water, mineral hydrocarbon oils, oleicacid, benzene and chloroform, by partial solubility of said sodium saltsin hydrochloric acid and, by formation of water-insoluble calcium andbarium salts; heating said aqueous dispersion to boiling; adding waterto give an aqueous suspension containing a total quantity of watervarying within the range of 8 to 50 parts by weight in direct proportionto the quantity of oleic acid subsequently added; bringing 2 to 50 partsby weight of liquid oleic acid gradually into reaction with saidlast-mentioned aqueous dispersion by agitation of the mixture at aninitial temperature of at least 50 C.; and continuing agitation untilthe product is homogeneous on standing.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,678,311 Adams July 24, 1928 2,069,365 Handy Feb. 2, 19372,163,701 Ried June 27, 1939 2,164,063 Handy June 27, 1939 2,202,601Ried May 28, 1940 2,259,420 Hills Oct. 14, 1941 2,433,258 Booth et al.Dec. 23, 1947

